(v2) react-loadable-ssr-addon getBundles error

🐛 Bug Report

Running docusaurus build in a project with swizzled DocItem and DocPage components throws an when server code is being evaluated.

Have you read the Contributing Guidelines on issues?

Yes

To Reproduce

1. Create a new project using @docusaurus/init with classic template
2. Remove blog directory
3. yarn docusaurus swizzle @docusaurus/theme-classic DocItem
4. yarn docusaurus swizzle @docusaurus/theme-classic DocPage
5. Run yarn build

Expected behavior

docusaurus build to finish successfully

Actual Behavior

Failed CI logs

$ docusaurus build
Creating an optimized production build...
[info] [webpackbar] Compiling Client
[info] [webpackbar] Compiling Server
[success] [webpackbar] Client: Compiled successfully in 12.23s
[success] [webpackbar] Server: Compiled with some errors in 13.57s

(undefined) TypeError: Cannot convert undefined or null to object

    at Function.keys (<anonymous>)
TypeError: Cannot convert undefined or null to object
    at main:19364:12
    at Array.reduce (<anonymous>)
    at getBundles (main:19363:20)
    at serverEntry_render (main:35231:113)
(undefined) TypeError: Cannot convert undefined or null to object
    at Function.keys (<anonymous>)
    at main:19364:12
    at Array.reduce (<anonymous>)
    at getBundles (main:19363:20)
    at serverEntry_render (main:35231:113)
(undefined) TypeError: Cannot convert undefined or null to object
    at Function.keys (<anonymous>)
    at main:19364:12
    at Array.reduce (<anonymous>)
    at getBundles (main:19363:20)
    at serverEntry_render (main:35231:113)
(undefined) TypeError: Cannot convert undefined or null to object
    at Function.keys (<anonymous>)
    at main:19364:12
    at Array.reduce (<anonymous>)
    at getBundles (main:19363:20)
    at serverEntry_render (main:35231:113)
(undefined) TypeError: Cannot convert undefined or null to object
    at Function.keys (<anonymous>)
    at main:19364:12
    at Array.reduce (<anonymous>)
    at getBundles (main:19363:20)
    at serverEntry_render (main:35231:113)
Error: Failed to compile with errors.
    at /home/runner/work/docusaurus-issue/docusaurus-issue/node_modules/@docusaurus/core/lib/commands/build.js:38:24
    at finalCallback (/home/runner/work/docusaurus-issue/docusaurus-issue/node_modules/webpack/lib/MultiCompiler.js:254:12)
    at /home/runner/work/docusaurus-issue/docusaurus-issue/node_modules/webpack/lib/MultiCompiler.js:277:6
    at done (/home/runner/work/docusaurus-issue/docusaurus-issue/node_modules/neo-async/async.js:2931:13)
    at runCompilers (/home/runner/work/docusaurus-issue/docusaurus-issue/node_modules/webpack/lib/MultiCompiler.js:181:48)
    at /home/runner/work/docusaurus-issue/docusaurus-issue/node_modules/webpack/lib/MultiCompiler.js:188:7
    at /home/runner/work/docusaurus-issue/docusaurus-issue/node_modules/webpack/lib/MultiCompiler.js:270:7
    at finalCallback (/home/runner/work/docusaurus-issue/docusaurus-issue/node_modules/webpack/lib/Compiler.js:257:39)
    at /home/runner/work/docusaurus-issue/docusaurus-issue/node_modules/webpack/lib/Compiler.js:273:13
    at AsyncSeriesHook.eval [as callAsync] (eval at create (/home/runner/work/docusaurus-issue/docusaurus-issue/node_modules/tapable/lib/HookCodeFactory.js:33:10), <anonymous>:42:1)
    at AsyncSeriesHook.lazyCompileHook (/home/runner/work/docusaurus-issue/docusaurus-issue/node_modules/tapable/lib/Hook.js:154:20)
    at onCompiled (/home/runner/work/docusaurus-issue/docusaurus-issue/node_modules/webpack/lib/Compiler.js:271:21)
    at /home/runner/work/docusaurus-issue/docusaurus-issue/node_modules/webpack/lib/Compiler.js:681:15
    at AsyncSeriesHook.eval [as callAsync] (eval at create (/home/runner/work/docusaurus-issue/docusaurus-issue/node_modules/tapable/lib/HookCodeFactory.js:33:10), <anonymous>:6:1)
    at AsyncSeriesHook.lazyCompileHook (/home/runner/work/docusaurus-issue/docusaurus-issue/node_modules/tapable/lib/Hook.js:154:20)
    at /home/runner/work/docusaurus-issue/docusaurus-issue/node_modules/webpack/lib/Compiler.js:678:31
    at Function.keys (<anonymous>)
    at Array.reduce (<anonymous>)TypeError: Cannot convert undefined or null to object
    at Function.keys (<anonymous>)
    at Array.reduce (<anonymous>)TypeError: Cannot convert undefined or null to object
    at Function.keys (<anonymous>)
    at Array.reduce (<anonymous>)TypeError: Cannot convert undefined or null to object
    at Function.keys (<anonymous>)
    at Array.reduce (<anonymous>)TypeError: Cannot convert undefined or null to object
    at Function.keys (<anonymous>)
    at Array.reduce (<anonymous>)

Your Environment

• Docusaurus version used: 2.0.0-alpha.56
• Environment name and version (e.g. Chrome 78.0.3904.108, Node.js 10.17.0): Node.js v14.3.0
• Operating system and version (desktop or mobile): Linux

Reproducible Demo

https://github.com/ark120202/docusaurus-issue

[ark120202]

I have tried it on the repository where I have found that issue originally (https://github.com/ModDota/moddota.github.io/commit/ddd4b3a2ff3a9ae14603240588ba6c4456f4fc25)

[ark120202]

Yes, this patch also makes it work for me